The present invention relates to a method for producing a pattern-forming body comprising a pattern having different characteristics on the surface that can be used in various applications such as a color filter.
Various methods for producing pattern-forming bodies having various patterns such as graphics, images, texts and circuits on substrates have been proposed.
For example, when discussing a case of printing as an example, a planographic plate employed in a planographic printing which is one of the printing methods is employed in such a manner that a plate having a pattern comprising an ink-receiving lipophilic part and a printing ink-repelling part is produced and used to form an image of the ink to be printed on the lipophilic part and the image thus formed is then transferred for example onto a paper whereby accomplishing the printing. In such a printing, a pattern such as a text or figure is formed on such a master printing plate to produce a printing plate as a pattern-forming body which is then fitted in the printing machine and used. Many types of the master plates for an offset press which is a representative planographic process have been proposed.
An offset printing plate can be produced by a method in which a master plate is exposed via a mask on which a pattern was depicted and then developed or by a method in which an electrophotographic process is employed to effect a direct exposure whereby making a plate directly on the master plate. An electrophotographic offset master plate is produced by a method in which a photoconductive layer having a photoconductive particle such as zinc oxide and a binder resin as main components are formed on a conductive substrate to form a photosensitive body with which the exposure is effected by an electrophotographic process to form a highly lipophilic image on the surface of the photosensitive body, which is then treated with a fat-insensitizing solution to make a non-image part hydrophilic whereby obtaining an offset master plate, i.e., a pattern-forming body. The hydrophilic part is immersed for example in water to be imparted with a lipophobicity, while a lipophilic image part receives a printing ink which is then transferred for example to a paper. However, various post-exposure treatments for example with fat-insensitizing solutions are required for forming a pattern.
A method for producing a planographic master plate employing a heat mode recording material capable of forming a pattern comprising a highly ink-receiving part and an ink-repelling part by means of a laser irradiation has also been proposed. While the heat mode recording material is advantageous due to the ability of producing a printing plate only by forming an image simply by a laser beam without processes for example of development, it poses problems associated with adjustment of the laser intensity, disposal of the residues such as a laser-degenerated solid substance, printing resistance and the like.
Another known method for forming a highly minute pattern is a method for producing a pattern-forming body by photolithography which forms an intended pattern directly by the exposure of a photoresist, involving a process for exposing a photoresist coated on a substrate with a pattern followed by developing the photoresist followed for example by etching or using a functional substance as a photoresist.
While a highly minute pattern formation by the photolithography is employed for example in a method for forming a colored pattern of a color filter employed in a liquid crystal display, forming a microlens, producing a minute electric circuit board, and producing a chrome mask employed in exposing a pattern, such a method poses a problem for example of the waste liquid disposal due to the requirement of the post-exposure developing with a liquid developer or etching associated with the use of a photoresist, as well as a problematic degradation of a functional substance, if employed as a photoresist, due to alkaline solution employed for developing.
Although an attempt is made to form a highly minute pattern of a color filter and the like by printing, a pattern formed by the printing is problematic with regard to the position accuracy and the like, resulting in a difficulty in forming a pattern at a high accuracy.
On the other hand, a method for producing a pattern-forming body in which a pattern is formed using a substance whose wettability is changed by the effect of a photocatalyst has been investigated by us for the purpose of solving the problems described above. Nevertheless, the conventional method for producing a pattern-forming body using a photocatalyst can not avoid the aspect that the resultant pattern-forming body itself contains the photocatalyst which may affect some types of the pattern-forming body adversely.
When forming a pattern using a substance whose wettability is changed by the effect of a catalyst as described above, the exposure should be conducted in a pattern usually employing a photomask. However, the exposure via a photomask needs to position the photomask precisely, resulting in a problem associated with the accuracy of the positioning especially when forming a highly minute pattern. The use of a photomask may also require a distance to be provided between the surface of the pattern irradiation target layer whose wettability is changed and the photomask or may involve other intermediate layers. In such a case, a disadvantage may be experienced in forming a highly minute pattern due to the scattering of the light irradiated.